const ostPop = document.querySelector('.ost-pop');
const menu2 = document.querySelector('.menu2');

menu2.onmouseenter = () => {
  ostPop.style.height = 'auto';
  const { height } = ostPop.getBoundingClientRect();
  console.log(height);
  ostPop.style.height = 0;
  ostPop.style.transition = '0.3s';
  ostPop.getBoundingClientRect();
  ostPop.style.height = height + 'px';
};

menu2.addEventListener('mouseleave', () => {
  ostPop.style.height = 0;
})
